I understand the concept of MLC vs SLC SSD drives and why the write speeds would slow down without TRIM support such as in a RAID configuration, but why would the read speeds slow down too. It's not like it needs to erase blocks first in order to read them. It seems like only write speeds would be affected, not read. Yet benchmarks always seem to show speed degradation in both read and write, why is this?
Easy! If the write is slowed down,then before it can do anything else,it has to erase in order. Even when you have quad compared to dual core you still have to wait until the cpu does its job. Every thing is slowed down because the cpu has attend to the erase order first.